Submarine antenna structure



July 10, 1951 o. E. DUNLAP, JR

SUBMARINE ANTENNA STRUCTURE 2 Sheets-Sheet 1 Filed April 22, 1950 INVENTOR E. fizmla Orrin ATTORNEY July 10, 1951 o. E. DUNLAP, JR 2,560,218

SUBMARINE ANTENNA STRUCTURE Fil ed April 22, 1950 2 Sheets-Sheet 2 INVENTOR 01min Dzzzziqp, J2: BY T" 5 ATTORN EY Patented July 10, 1951 2,560,218 SUBMARINE ANTENNA STRUCTURE Orrin E. Dunlap, Jr., Great Neck, N. Y., assignor to Radio Corporation of America, a corporation of Delaware Application April 22, 1950, Serial No. 157,529

9 Claims. 1

The invention relates to reflector structures for antennas. It especially pertains to reflectors for high frequency directive antennas mounted on submarines.

Many high frequency systems require intense concentrations of radio waves in narrow beams. For such applications dipole antennas, guidedwave horn radiators and receptor elements are frequently employed. Inherently, these elements radiate or receive radiations over very wide angles. Concentration of radiant action is secured by employing a reflecting structure behind the antenna.

One of the preferred types of reflecting structure employed is the parabolic reflector. This reflector has the form of a bowl of conductive material, large in diameter and relatively shallow in depth. The surface of the bowl is usually a surface of revolution whose generatrix, is in the form of a parabola. The radiating or receiving element, as the case may be, is located at the focus of the parabola. For operation at 300 megacycles per second, the parabolic reflector is made large, usually of the order of flve feet or more in diameter in order to secure effective action.

A reflector of such dimensions inherently offers severe drag in installations where theantenna moves at high speeds. For example, in aircraft installations, the tremendous airstream pressure that would be built up precludes exposure. As a result, the parabolic system when employed on aircraft must be reduced in size, with concomitant loss of effectiveness, so that it may be mounted within the fuselage.

Another installation in which the problem of drag is particularly troublesome is in the case 'of high frequency radiation systems for submarines. Heretofore, reflectors for submarine antenna systems have been built in the form of perforated sheets or grids or gratings. This construction is employed in order to permit water to pass directly through the reflector and thereby reduce drag. Such practice, however, reduces the electrical efficiency of the antenna sytem because of electrical losses introduced by the openings in' the reflector. To compensate for this loss and secure suitably effective action, the size of the reflector is increased over that required were the reflector solid. This, however, involves increased drag and an increase in weight, both of which are highly undesirable in the operation of submarines.

The purpose of the invention is to provide a reflector for a submarine antenna system which,

2 while not subject to the foregoing disadvantages, will have dimensions sufliciently large to provide optimum efiiciency in operation. A more specific object of the invention is to provide a reflector capable of being reduced in effective size when the system is not in operation.

Still another object of the invention is to provide a reflector for a submarine antenna system which can be folded into a streamlined configuration when the system is not in operation.

Other objects and advantages of the invention will be evident as the more detailed description of the invention proceeds.

Briefly, in accordance with the invention, a substantially conventional reflector structure is divided into two symmetrical portions pivotally arranged with respect to one another. Corresponding edges of the two reflector portions are mirror images of each other. At least one further structural member is pivotally arranged with respect to the symmetrical members. This member has such configuration that upon closure in the non-operating position, the entire structure is substantiallystreamlined. The two symmetrical portions folded together form a semistreamlined body open at one end only. The open end is then covered by at least a third member to complete the streamlined configuration. Thus drag is minimized for the structure in the non-operating or submerged position while providing maximum electrical efficiency when in operation on the surface.

In the basic embodiment of the invention, the novel reflector-housing arrangement is manually opened and closed. In practice, however, it is contemplated that an additional mechanism, preferably remotely controlled, will be employed to open and close the structure. Although contemplating remote control, a simplified, springloaded. opening and closing arrangement actin automatically in the desired manner is provided. Remotely controlled means to lock the structure in its operating and non-operating positions is also contemplated.

It should be clear that my invention is equally applicable to acoustic and light energy directive systems in all cases in which perforated reflectors cannot be tolerated.

More fully, the invention, both as to its organization and manner of operation, together with further objectives and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing forming a part of the specifica tion and in which:

Fig. 1 is a front view of an antenna and reflector system modified according to the invention shown in the operating position;

Fig. 2 is a side View of the arrangement of Fig. 1 showing additional details of the modification according to the invention in the nonoperating position;

Fig. 3 is a rear view of the arrangement of Fig. 1, also showing details of the modification in the operating position;

Fig. 4 is a front view of an alternate embodiment of the invention in operating condition;

Fig. 5 is a front view of the arrangement of Fig. 4 in non-operating condition;

Fig. 6 is a front view of an alternate embodiment of the invention in operating condition; and

Fig. 7 is a side view of the arrangement of Fig. 6 in non-operating condition.

Referring to Fig. 1, there is shown a radiator or receptor element in the form of a Wave-guide horn 2!. A parabolic reflector 23 is placed in front of horn 2! with the latter at the focus of the parabola. Preferably, horn 2! and reflector 23 are arranged to be rotated as a unit on a rotatable pedestal 25. A stanchion 2! serves to support pedestal 25 above deck, and it also serves as a conduit for electrical and mechanical connections to apparatus below deck. In transmitting, energy from transmitting apparatus (not shown) is applied to horn 2! from which it is directed to reflector 23. Reflector 23 concentrates the energy in a narrow beam pointed along the axis of the reflector. Received energy intercepted along the axis of the reflector 23 is directed into horn 2! and to a receiver (not shown).

The arrangement thus far described is entirely conventional and forms no part of the invention itself. Additional information on such arrangements is available by reference to the book entitled Radar, by Orrin E. Dunlap, Jr., published in 1946 by Harper and Brothers, publishers.

The reflector according to the invention is divided into two symmetrical portions 3! and 32, the dividing line between portions 3! and 32 lying in a single plane. At the intersection of the dividing plane and the plane defined by the front edge of reflector 23, the portions 3! and 32 are pivotally joined by hinge members 33 and 35. These hinge members may be of any known form suitable for the purpose. Hinge member 35 is made sufliciently large and in such manner of construction that a waveguide 4'! which is connected to horn 2! may be brought through. It is understood, of course, that Waveguide 4'! will have a rotating choke joint interposed therein within pedestal 25. In more elaborate embodiments of the invention it is contemplated that additional electrical or mechanical connections may be brought through hinge member 35 for such purposes as necessary and desirable, depending upon the application to which the antenna system is put.

To assume the non-operating or submerged position, reflector portions 3! and 32 are rotated about the axis defined by hinge members 33 and 35 to bring the forward edges of portions 3! and 32 together directly to the rear of horn 2!. In this manner reflector portions 3! and 32 no longer form a parabolic reflector structure. They exhibit instead a clamshell form which is open to the front of horn 2!. According to the invention, this arrangement is then converted into a closed, streamlined housing structure by the addition of a further member 31. Closure member 3! preferably is pivotally arranged on reflector portion 32 as illustrated in Figs. 2 and 3.

Figs. 2 and 3 show, respectively, a rear view in the operating position and a side View in the submerged or streamlined position. Streamlining member 3'! is mounted on reflector portion 32 by means of hinges ll. It is urged into its respective operating and non-operating positions by means of a coil spring 43. It should be understood that one of the reflector portions may be rigidly fastened to pedestal 25 and the other only rotated. It will be obvious that only relative movement of the two portions is necessary. The edge of member 3? opposite hinges 4! is made to ride lightly on the surface of reflector portion 3! so that relative movement of reflector portions 3!, 32 will open or close the entire structure in the manner desired. It should be understood, of course, that reinforcing members may be applied to the structure to render it self-supporting, as shown, for example, by rib members Other structural members may be used to prevent wear between parts, as for example between portions 3! and 31.

That the invention is not limited to the use of dish-shaped parabolic reflectors is shown with reference to Figs. 4-7. Here are shown cylindroparabolic reflectors modified according to the invention. In the embodiment shown in the operating position in 4, energy translated in a coaxial transmission line 23 is radiated by a conventional half-wave dipole element 5! located at the focus of a reflector comprising two portions 6! and 62. The reflector thus comprised is a semi-cylinder having the cross-section of a parabola or other desired form. In some instances it may be desirable to place a smaller reflector in front of the dipole to reflect energy back to the main reflector 6!32. A further member 6'! is hinged to member 32 in the same manner that member 3'! is hinged to portion 32 in the arrangements shown in Figs. 1-3.

In the submerged position as shown in Fig. 5, portions 6! and 62 are brought together with the forward edges coincident exactly as for the arrangements of Figs. 1-3, a spring 63 causing menuber 61 to close the entire structure to provide a streamlined appearance. In the embodiments shown in Figs. 4 and 5, the top and bottom of the reflector must be enclosed and plate 'l!!6 are utilized for this purpose. The use of conductive plates may not be feasible because of the adverse effect on the radiated energy. Plate ll-M may then be made of non-conducting material, such as polystyrene, for example. It is not necessary that these plates be perpendicular to the cylindrical axis of the reflector nor that they be fiat. It is only essential that they be made to close upon each other in order to form a completely water-tight hollow structure.

A balanced version is shown in the arrangement of Figs. 6 and 7. The streamlining structure in these figures is formed in two portions 9! and 92 which open outwardly to permit portions 6! and 62 to be set in the operating position. In this construction portions 9! and 92 are pivoted on pin 93 supported in relation to the rotational axis of portions 6! and 62 by a U-shaped supporting bar 95. Pin 93 is arranged to move back in slots 9'! against springs 99 in order to provide room for portions 9! and 92 to be swung outwardly. Springs 99 also act to urge the four portions 6!, 62, 9! and 92 into firm water-tight engagement in the submerged position. Such an arrangement permits beveled or interlocking edges to be used with only .small additional complication in mechanism.

Streamlining members 31, 61, 9| and 92 need not be made of the same material as reflector portions 3!, 32, 6! and 62. Nor need they be made hollow, although that form is preferred. In practice it is contemplated that mechanisms for forcing sections 9! and 92 apart initially to permit portions GI and 62 to be opened will be mounted inside sections 9| and 92 and cntrolled from below deck.

The edges of the various portions of the streamlined structure are of course arranged to coincide at all points. These edges arefitted with means rendering them water tight in the submerged position. Such means, being commonly known, are not shown or described in detail as they form no part of the invention itself.

Other refinements are within the scope of the invention. One such involves some form of track or cam and lever arrangement for guiding the relative movement of the several portions of the structure of the invention in their travel. Also, it is contemplated that one or more locking means will be provided for maintaining the structures in the operating or non-operating positions. The structures may thus be subjected to the expected vibrations and accompanying stresses without impairment of efficiency. The arrangements shown in the drawing are readily foldable manually from the operating to the non-operating positions and vice versa. It is contemplated in practice, however, that hinge arrangement 35 will have members extending down through pedestal 25 and stanchion 21. The reflector structure may in this manner be opened and closed by means of apparatus located below deck in the submarine.

While the invention has been described in terms of express embodiments, it should be understood, therefore, that many obvious modifications thereof will be self evident to those skilled in the art without departing from the spirit and scope of the invention.

The invention claimed is:

l. A reflector for a wave energy directive system which in closed position forms a hollow housing, comprising a hollow receptacle having an open end and divided longitudinally into two complemental portions hinged together at the open end division points, the said portions being adapted. to swing outwardly around the said hinge to form a reflector, and a closure for said receptacle. the said closure being pivoted on one of said portions to swing away from said portions when the latter are swung outwardly to reflector forming position.

2. A reflector-housing arrangement forgwave energy directive system, including two complementary conductive concavo-convex surface elements pivotally joined together along an axis, ,said elements each having two edges lying on planes passing through said axis to permit said elements to be selectively positioned in two positions with corresponding edges coincident in each of said positions, said elements forming a reflector in one of said positions, a member having edges substantially coincident with the edges said elements which are apart when said elements are in the other of said positions to form a housing; said member having a configuration providing a streamlined configuration for said housing.

3. A reflector-housing structure for a wave energy propagation system, including a pair of symmetrical solid geometrical surface conductive members, each of said members having at least two non-linear edges defining two intersecting planes, said members being pivotally joined at the intersection of said planes to permit selective positioning of said members with corresponding edges abutting, said members forming a reflector element for propagation of said wave energy with one pair of said two pairs of corresponding edges abutting, and at least one further geometrical solid surface element having edges conforming to the mirror duplicate of said one pair of corresponding edges of said members when in the non-abutting position, said further element having a geometrical configuration and abutting on said one pair of corresponding edges to provide a streamlined housing for said propagation system.

4. A reflector-housing arrangement for an antenna system, including two complementary thin conductive surface elements pivotally joined together along an axis, said elements each having two edges lying on planes passing through said axis, the edges of one of said elements being mirror images of the corresponding edges of the other of said elements to permit said elements to be selectively positioned in two positions with corresponding edges coincident in each of said positions, said elements forming a reflector for the antenna in one of said positions, the axis of said reflector being normal to the first-said axis, a member having edges coincident with the edges of said elements which are apart when said elements are in the other of said positions to form a housing for the antenna; said member having a configuration providing a substantially streamlined configuration for said. housing.

5. A reflector-housing structure for an antenna system, including a pair of symmetrical solid geometrical surface conductive members, each of said members having at least two non-linear edges defining two' intersecting planes, corresponding edges of said members being counterparts, said members being pivotally joined at the intersection of said planes to permit selective positioning of said members in two positions with corresponding edges coincident in each of said positions, said members forming a reflector element in one of said positions with one pair of said two pairs of corresponding edges abutting, and at least one further geometrical solid surface element having edges conforming to mirror duplicate of said one pair of corresponding edges of said members when non coincident, said further element having a geometrical configuration and edges coincident with said one pair of corresponding edges to provide a streamlined housing for said antenna system.

6. A reflector-housing arrangement for a sub: marine antenna system, including a hollow parabolic reflector having the forward edge thereof lying in a plane normal to the axis of said reflector, said reflector being bisected in a plane normal to the first said plane and passing through said axis to form two portions, said portions being pivotally fastened together at points on said reflector determined by the intersection of saidplanes to permit said portions to be brought together selectively at the rear edges defined by the second mentioned plane and at said forward edges defined by the first mentioned plane, and a member having edges coincident with said rear edges of said two portions when in the position in which the forward edges are together to close said structure and form a housing for said antenna system, said member having an external surface providing a substantially streamlined configuration to said housing.

7. A reflector-housing arrangement for a submarine antenna system, including a hollow parabolic reflector having the forward edge thereof lying in a plane normal to the axis of said reflector, the surface of said reflector being a surface of revolution of a parabola, an antenna ele-. ment located at the focal point of said parabola, said reflector being bisected in a plane normal to the first said plane and passing through said axis to form two portions, said portions being pivotally fastened together at points on said reflector determined by the intersection of said planes to permit said portions to be brought together selectively at the rear edges defined by the second mentioned plane and at said forward edges defined by the first mentioned plane, and a member pivotally arranged on one of said portions having edges coincident with said rear edges of said two portions when in the position in which the forward edges are brought together to close said structure and form a housing for said antenna element, said member having an external surface providing a substantially streamlined configuration to said housing.

8. A reflector-housing arrangement for asubmarine antenna system, including a hollow cylindro-parabolic reflector having the forward edge thereof lying in a plane normal to the axis of said reflector, a portion of the surface of said reflector being defined by a generatrix moved parallel to itself along the line of a parabola, an antenna element located at the focus of said parabola, said reflector being bisected in a plane normal to the first said plane and passing through said axis, to form two portions, said portions being pivotally fastened together at points on said reflector determined by the intersection of said planes to permit said portions to be brought together selectively at the rear edges defined by the second mentioned plane and at 8 i said forward edges defined by the first mentioned p1ane;-and a member pivotally arranged on one of said portions and having edges coincident with said rear edges of said two portions when in the position in which the forward edges are together to close said structure and form a housing for said antenna element, said member having an external surface providing a streamlined configuration to said housing.

9. A reflector-housing arrangement for a submarine antenna system, including a hollow parabolic reflector having the forward edge thereof lying in a plane normal to the axis of said reflector, said reflector being bisected in a plane normal to the first said plane and passing through said axis, to form two portions, said portions being pivotally fastened together on an axis defined by points on said reflector determined by the intersection of said planes to permit said portions to be brought together selectively at the rear edges defined by the second mentioned plane and at said forward edges defined by the first said plane, and a pair of members having edges coincident with said rear edges of said two portions when in the position in which the forward edges are together to close said structure and form a housing for said antenna system, said members being mutually pivotally arranged on an axis parallel to the first mentioned axis, said members having external surfaces providing a stream lined configuration to said housing.

ORRIN E. DUNLAP, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,066,419 Rey July 1, 1913 1,935,045 Doane Nov. 14, 1933 2,463,517 Chromak June 30, 1945 

